Traditionally, the pigments of choice for dark eye makeup, particularly eyeliner and mascara, have been inorganic oxides, for example, iron oxide or titanium dioxide. Although these pigments are capable of producing the darkest desirable shades, in particular, a true black, these materials come in the form of large particles. This form can be cumbersome to work with, in particular when forming a product which is intended to go on in liquid form through a narrow applicator. For example, in a typical eyeliner "pen", the oxide particles have a tendency to clog the nib of the pen, so that the liquid eyeliner does not flow smoothly, or at all, through the nib and onto the skin. In addition, even if flow should continue, the black pigment will tend to be filtered out, thereby diluting the color to an off-brown.
More recently, a group of organic pigments, namely D&C and FD&C pigments, have also been used in the preparation of cosmetics in which a dark color is desirable. The advantage of these pigments is that they do not have the large particulate form of the inorganic pigments; however, the major limitation of these pigments is that they are incapable of producing a true black color. In the present context, "true black" is defined as the absolute non-reflectance of color, i.e., a reading on a spectrophotometer of less than 4.75. The inability to make a true black with organic pigments is a serious drawback in attempting to make a typical eyeliner or mascara, and therefore, limits the utility of these materials.
There is thus still a need for pigment which can provide the desired black or very dark colors for use in eyeliner and mascara, and yet which will be easily adaptable to a liquid eyeliner formulation. The present invention provides a useful alternative to the traditionally used pigments for eye products.